<template>
	<view>
		<my-search  @search="gotoSearch" ></my-search>
		<view class="scroll-view-container">
		      <!-- 左侧的滚动视图区域 -->
		      <scroll-view class="left-scroll-view" scroll-y :style="{height: wh + 'px'}" >
				<!-- <view class="left-scroll-view-item"  v-for="(item, i) in cateList" :key="i">{{item.cat_name}}</view> -->
				 <block v-for="(item, i) in cateList" :key="i">
				    <view :class="['left-scroll-view-item', i == active ? 'active' : '']"  @click="activeChanged(i)">{{item.cat_name}}</view>
				  </block>
		      </scroll-view>
		      <!-- 右侧的滚动视图区域 -->
		      <scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px'}" :scroll-top="scrollTop">
		        <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
		           <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
					<view class="cate-lv3-list">
						<view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
							<!-- 图片 -->
							<image :src="item3.cat_icon"></image>
							<!-- 文本 -->
							<text>{{item3.cat_name}}</text>
						</view>
					</view>
				</view>
		      </scroll-view>
		    </view>
	</view>
</template>

<script>
	import badgeMix from '@/mixins/tabbar-badge.js'
	export default {
		mixins:[badgeMix],
		onLoad() {
		      // 获取当前系统的信息
		      const sysInfo = uni.getSystemInfoSync()
			  console.log(sysInfo)
		       // 可用高度 = 屏幕高度 - navigationBar高度 - tabBar高度 - 自定义的search组件高度
		      this.wh = sysInfo.windowHeight - 50
			  console.log(this.wh)
			  
			  this.getCateList()
		},
		data() {
			return {
				// 窗口的可用高度 = 屏幕高度 - navigationBar高度 - tabBar 高度
				wh: 0,
				cateList: [],
				cateLevel2: [],
				// 当前选中项的索引，默认让第一项被选中
				active: 0,
				// 滚动条距离顶部的距离
				scrollTop: 0
			};
		},
		methods:{
			getCateList(){
				uni.$http.get("/api/public/v1/categories").then(res=>{
					this.cateList = res.data.message
					// 为二级分类赋值
					this.cateLevel2 = res.data.message[0].children
					console.log(res)
				})
			},
			activeChanged(i){
				this.active = i
				this.cateLevel2 = this.cateList[i].children
				
				// 让 scrollTop 的值在 0 与 1 之间切换
				this.scrollTop = this.scrollTop === 0 ? 1 : 0
				// 可以简化为如下的代码：
				// this.scrollTop = this.scrollTop ? 0 : 1
			},
			gotoGoodsList(item) {
			  uni.navigateTo({
			    url: `/subpkg/goodsDetail/goodsDetail?goods_id=${item.goods_id}`
			  })
			},
			gotoSearch() {
			    uni.navigateTo({
			       url: '/subpkg/search/search'
			    })
			}
		}
	}
</script>

<style lang="scss">
.scroll-view-container {
	display: flex;
	.left-scroll-view {
	    width: 120px;
		.left-scroll-view-item {
		    line-height: 120rpx;
		    background-color: #f7f7f7;
		    text-align: center;
		    font-size: 24rpx;
		}
		// 激活项的样式
		& .active {
			background-color: #ffffff;
			position: relative;
			&::before {
			  content: ' ';
			  display: block;
			  width: 3px;
			  height: 30px;
			  background-color: #c00000;
			  position: absolute;
			  left: 0;
			  top: 50%;
			  transform: translateY(-50%);
			}
		}	
	}
}
.cate-lv2-title {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}
.cate-lv3-list {
  display: flex;
  flex-wrap: wrap;

  .cate-lv3-item {
    width: 33.33%;
    margin-bottom: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;

    image {
      width: 60px;
      height: 60px;
    }

    text {
      font-size: 12px;
	  margin-left: 5px;
    }
  }
}
</style>
